(1) Technical Field:
This invention relates to key cutting machines and more particularly concerns a tubular key cutting machine wherein a key bite is milled into a key blank in a direction oriented radially to the key blank tube.
(2) Description of the Prior Art:
Tubular keys for operation of axial pin tumbler locks such as the type generally described in U.S. Pat. No. 3,504,748 are in general use and machines for cutting or machining such tubular keys have been heretofore proposed and are subject of several U.S. Pat. Nos. including 3,418,882; 3,818,798 and 4,022,107.
In each of these disclosures the tubular key blanks are mounted adjustably relative to a rotatable milling tool and the patents include indexing means by which the relative positioning of the tubular key blanks and the milling tool can be predetermined and repeatedly reset. In actual practice the indexing means disclosed in the prior art patents is not sufficiently accurate to consistently reproduce usable tubular keys. The lack of accuracy in the prior art devices is occasioned primarily by the plurality of parts that are movably interposed between the actual indexing means and the actual milling or cutting device and/or the tubular key blank.